Brain 'Pacemaker' Tickles Your Happy Nerve

[ramonmercado]

Brain 'Pacemaker' Tickles Your Happy Nerve
Marty Graham 05.23.07 | 2:00 AM


The vagus nerve stimulator power pack is implanted near the collarbone, and wired to the left side nerve -- always the left, since the right side goes directly to the heart.
Illustration: Cyberonics Inc.
SAN DIEGO -- A novel medical technique that smuggles an electrical charge into the brain through the vagus nerve is proving at least as effective as medication in controlling severe depression, psychiatrists say.

In vagus nerve stimulation, or VNS, a two-inch diameter, .25 inch thick disk is surgically tucked under the skin near the left collarbone, then wired upward to the vagus nerve in the neck. The battery-operated disk delivers intermittent, rhythmic pulses to the nerve -- whose name means "wandering" in Latin -- that reaches a half dozen areas of the brain critical to treating depression, according to Dr. Darin Dougherty of Massachusetts General Hospital.

"Instead of prescribing milligrams I'm prescribing milliamps," Dougherty says. The implanted disc is programmed and reprogrammed with a wand held over the skin. Data on each patient about the intensity and frequency of the pulse and device settings is stored in individual memory cards slotted into in a handheld computer linked to the wand.

VNS has been used for 10 years to treat epilepsy, where it can cut the number of seizures for some patients by about 40 percent. Doctors began to suspect it held potential for treating severe depression when patients clung to the device, even when it wasn't helping their epilepsy.

"We asked (epilepsy) patients who weren't being helped if we could remove the device and by and large, the patients said, 'No, no, don't take this away,'" says Dr. Mitchel Kling of the National Institutes for Health. "In some cases where there wasn't good seizure control, patients' mood problems stabilized."

The technique won FDA approval as a depression treatment in July 2005. Since then, about 3,000 depression patients have been wired, according to Cyberonics, the Houston-based manufacturer of the device. Doctors gathered at the American Psychiatric Association conference here say they've seen measurable results.

In an October 2005 study, about a third of the severely depressed patients responded well, and almost half went into remission. Ninety-one percent maintained their recovery nine months later, and some patients who didn't report immediate benefits showed improvement and even remission later on.

Researchers know the treatment stimulates norepinephrine and serotonin centers, now treated with pharma at a tepid success rate, and increases blood flow and neuron activity. But they candidly say they don't fully understand why VNS works.

Once healed from surgery, patients report their voices get gravelly during the pulse cycle, usually five of every 30 seconds. If that becomes a problem -- during public speaking, for example -- the device is designed with an off-switch: The patient can suspend the unit by placing a magnet over it, Dougherty says.

Batteries last eight to 12 years, Dougherty says, and drawbacks include a requirement that the patient avoid physical therapy ultrasounds that can heat up the wiring and damage the nerve -- though diagnostic ultrasound works fine -- and problems getting a full body MRI.

The implant neatly sidesteps one of the biggest problem of treating depression: the documented tendency for patients to abandon treatment over side effects or because they feel better.

http://www.wired.com/print/science/disc ... 7/05/nerve

 

[Slejpner]

I can see that fast becoming a must-have leisure item.

A bit like viagra, say.

 

[OneWingedBird]

patients report their voices get gravelly during the pulse cycle, usually five of every 30 seconds

for some terrible reason, i'm trying hard not to imagine that having an effect like a dalek modulator :shock:

 

[Philo_T]

"only a sophisticate would fear a tasp"

It's official, mankind is going extinct.

 

[ramonmercado]

Magnets 'help regrow brain cells'

Magnetic stimulation can be used for conditions such as depression
Magnets may offer a way to boost mental performance, US research suggests.
Scientists in New York promoted the growth of new neurons in the brains of mice using a magnetic stimulus in the region associated with memory.

Presenting the results at the American Academy for Neuroscience conference, the researchers said the results may lead to treatments for Alzheimer's.

However, if proven the technique is more likely to be a way of slowing progression of the disease than a cure.

Experts said the work was encouraging but would need to be replicated in humans.

Trans cranial magnetic stimulation (TMS) has been used to treat certain disorders, including depression and schizophrenia and to rehabilitate people after stroke.

It used a magnetic coil to introduce electrical fields in the brain, which activates or deactivates groups of neurons.

The work is particularly encouraging for the use of brain stimulation in chronic disease such as stroke and dementia

Professor Vincent Walsh

To look at the effect of TMS on growth of neurons, Dr Fortunato Battaglia and Dr Hoau-Yan Wang at City University in New York, gave mice the therapy for five days and then examined their brains, New Scientist magazine reported.

They found large increases in the proliferation of stem cells - immature cells that go on to develop into nerves and other kinds of tissue - in a part of the brain called the dentate gyrus hippocampus.

These cells divide throughout life and are believed to play a crucial role in memory and mood regulation.

In particular they found one receptor in the cells was activated.

A subsequent study which is due to be published shortly showed that the activity of this receptor declines in mice and humans with Alzheimer's disease.

Brain recovery

Taking the two studies together, Dr Battaglia said there were important implications for neurorehabilitation.

"When you have a stroke there is an area that is damaged and there are several ways your brain can recover.

"One is that the area which is not damaged will have to work more and it's that we can promote with brain stimulation."

He added that the hippocampus is much deeper in the brains of humans so it would be important to make sure the technique could produce the same effect as in mice.

"But it might improve symptoms or delay progression of things like Alzheimer's disease," he added.

Professor Vincent Walsh from the Institute of Cognitive Neuroscience at University College London said the findings were a good first step.

"There are lots of examples of TMS enhancing function in some way but we have never been able to explain the mechanics of how it might work.

"The work is particularly encouraging for the use of brain stimulation in chronic disease such as stroke and dementia.

"The challenge now is to find ways of combining stimulation with drug therapies."

Professor Clive Ballard, director of research at the Alzheimer's Society said: "This is a potentially interesting piece of work, but is a preliminary study in mice.

"Further research is now needed before we can find out if TMS is a useful treatment approach for Alzheimer's disease in humans."


http://news.bbc.co.uk/2/hi/health/6683757.stm

 

[RainyOcean]

I can see that fast becoming a must-have leisure item.

A bit like viagra, say.

At this point (at least in the U.S.) it's only being used in really severe cases of depression where the patient has tried lots of different medications with little to no success.

Personally the idea scares me because it's implanted in the neck, and can have negative side effects involving the vocal chord. Although I can see it being worth the risk if meds don't help.

 

[lemuria162]

patients report their voices get gravelly during the pulse cycle, usually five of every 30 seconds

for some terrible reason, i'm trying hard not to imagine that having an effect like a dalek modulator :shock:

But you could do a great 'Enfield Poltergeist' voice!

 

[Pietro_Mercurios]

I can see that fast becoming a must-have leisure item.

A bit like viagra, say.

There's already a whole sub-genre of SF about 'Wireheads' and I seem to remember some research, from the 1950's, or 60's, about lab rats, which had little wires implanted into their brains, to stimulate the vagus nerve, when they pressed a button.

Eventually, the rats spent so much time pressing their little buttons, that they didn't stop to eat, or even drink, so they starved to death.

Apparently, it was:

James Old and Peter Milner, "Positive reinforcement produced by electrical stimulation of septal area and other regions on the rat brain," Journal of comparative and physiological psychology. 47 (1954): 419-422.
http://www.museumofhoaxes.com/hoax/weblog/comments/4319/

http://www.medindia.net/news/healthinfocus/science_of_happiness.asp

...

In an early study conducted by James Old and Peter Milner of McGill University, rats repeatedly pressed a lever, sometimes as often as 2000 times / hr, to experience stimulation targeted at a specific area of the brain. During this period they refused to stop for feeding, drinking or acts of procreation. These areas, identified as the ‘pleasure centers’ of the brain, were found to be impaired in individuals with Parkinson’s disease. The signaling chemical, dopamine, was christened the ‘pleasure chemical’. It was later established by Kent Berridge of the University of Michigan that the electrodes actually kindled desire, rather than pleasure. The dopamine system was found to control desire while the opioid system, comprising of naturally occurring morphine- like compounds, encodes pleasure. ...

Could be an interesting new sideline, for the less salubrious sort of tattoo parlour, or back street cosmetic surgeon.



would the Vagus Nerve be what Las Vagus was named after, or is it the other way round?

 

[synchronicity]

So....where do I sign up?